Method for producing dichloropentafluoropropanes

ABSTRACT

A method for producing a dichloropentafluoropropane, which comprises reacting dichlorofluoromethane (R21) with tetrafluoroethylene (4F) in the presence of a Lewis acid catalyst for addition reaction to obtain dichloropentafluoropropane, wherein a halide containing at least one element selected from the group consisting of Sb, Nb, Ta, B, Ga, In, Zr, Hf and Ti, or AlBr 3 , or AlI 3 , is used as the Lewis acid.

This is a division of application Ser. No. 07/720,491, filed on Jul. 5,1991.

DESCRIPTION

1. Technical Field

The present invention relates to a method for producingdichloropentafluoropropanes (R225s). Hydrochlorofluoropropanes areexpected to be useful as foaming agents, cooling media or cleaningagents like conventional chlorofluorocarbons.

2. Background of the Invention

As a method for producing the dichloropentafluoropropanes (R225s), it isknown to synthesize 3,3-dichloro-1,1,1,2,2-pentafluoropropane (R225ca)and 1,3-dichloro-1,1,2,2,3-pentafluoropropane (R225cb) as shown below byadding tetrafluoroethylene to dichlorofluoromethane in the presence ofaluminum chloride: ##STR1## (O. Paleta et al., Collect, Czech. Chem.Commun., 36, 1867 (1971)). However, in this reaction,dichlorofluoromethane is disproportionated as shown by the followingformula, ##STR2## and by-product chloroform (R20) which is hardlyseparable by a usual method such as distillation is formed in a largeamount. Thus, this method has a disadvantage that a multi-steppurification process is required to obtain a product in high purity.

SUMMARY OF THE INVENTION

The present inventors have conducted extensive researches on a methodfor efficiently producing dichloropentafluoropropanes (R225s) and as aresult, have found it possible to obtain R225s in high yield by reactingtetrafluoroethylene with dichlorofluoromethane (R21) in the presence ofa Lewis acid catalyst selected from the group consisting of a halidecontaining at least one element selected from the group consisting ofSb, Nb, Ta, B, Ga, In, Zr, Hf and Ti; AlBr₃ ; AlI₃ ; or a fluoride ofthe formula:

    MX.sub.α F.sub.β

wherein M is one of atoms selected from Group VIa, Group Va and GroupIIIb, or a mixture of such atoms, X is one of Cl, Br and I atoms, or amixture of such atoms, α is a real number of 0<α<5, and β is a realnumber of 0<β≦3.5 in the case of Group IVa, a real number of 0<β≦4.5 inthe case of Group Va and a real number of 0<β≦2.5 in the case of GroupIIIb, provided that α+β= an integer of from 3 to 5.

The halide containing at least one element selected from the groupconsisting of Sb, Nb, Ta, B, Ga, In, Zr, Hf and Ti includes chloridessuch as SbCl₅, NbCl₅, TaCl₅, Bcl₃, GaCl₂, GaCl₃, ZrCl₄, HfCl₄, InCl₃ andTiCl₄, and partially fluorinated compounds of such chlorides; fluoridessuch as SbF₅, NbF₅, TaF₅ and BF₃, and partially chlorinated compounds ofsuch fluorides; bromides and iodides such as TaBr₅, AlBr₃, AlI₃, BBr₃,BI₃, GaBr₃, GaI₃, HfBr₄, HfI₄, InBr₃, InI₃ and TiBr₄, and partiallychlorinated or fluorinated compounds of such bromides or iodides. Thepartially fluorinated chlorides and partially chlorinated fluoridesinclude, for example, TiCl₂ F₂, TiClF₃ and ZrCl₂ F₂.

The fluoride of the formula MX.sub.α F.sub.β can readily be prepared bytreating a halide of the formula:

    MX.sub.α

wherein M is one of atoms selected from the group consisting of GroupIVa, Group Va and Group IIIb, or a mixture of such atoms, X is one ofCl, Br and I atoms, or a mixture of such atoms, α is α=4 in the case ofGroup IVa, α=5 in the case of Group Va, and α=3 in the case of GroupsIIIb, for example, a chloride such as BCl₃, AlCl₃, GaCl₃, InCl₃, TiCl₄,ZrCl₄, HfCl₄, NbCl₅ or TaCl₅, or a bromide or iodide such as GaBr₃,GaI₃, InBr₃, InI₃, TaBr₅, AlBr₃, AlI_(3l) , BBr₃, BI₃, TiBr₄, TiI₄,ZrBr₄, ZrI₄, HfBr₄, HfI₄, AlBr₃ or AlI₃, with a suitable fluorinatingagent, for example, a chlorofluorocarbon (CFC) such astrichlorofluoromethane (R11), dichlorodifluoromethane (R12) ortrichlorotrifluoromethane (R113), a hydrochlorofluorocarbon (HCFC) suchas dichlorofluoromethane (R21) or chlorodifluoromethane (furon 22),hydrogen fluoride or fluorine gas.

The treating conditions vary depending upon the halide and the fluorinesource. However, it is usual to employ at least an equimolar amount ofthe fluorine source to the halide.

The reaction temperature is usually from -50° to 200° C., preferablyfrom -20° to 100° C., when chlorofluoromethane orhydrochlorofluoromethane is employed, and usually from -20° to 200° C.,preferably from 0° to 150° C., when other fluorine source such ashydrogen fluoride is employed.

The reaction time is usually from 10 minutes to 2 weeks, preferably from1 hour to 1 day, when chlorofluoromethane or hydrochlorofluoromethane isemployed, and usually from 30 minutes to two weeks, preferably from onehour to one day, when other fluorine source such as hydrogen fluoride isemployed.

The content of fluorine atom contained in the fluoride of the formulaMX.sub.α F.sub.β is preferably selected to be within a proper range inorder to increase the yield of the dichloropentafluoropropanes whilesuppressing the production of chloroform. The range may vary dependingupon the particle size when the fluoride is solid. However, it isusually 0<β≦3.5, preferably 1<β≦3, in the case of Group IVa, usually0<β≦4.5, preferably 1≦β≦4, in the case of Group Va, and usually 0<β≦2.5,preferably 0.01≦β≦2, more preferably 0.1≦β≦2, in the case of Group IIIb.

The addition reaction of R21 to tetrafluoroethylene in the presence of aLewis acid catalyst can be conducted in an inert solvent such asperfluorobutyltetrahydrofuran. However, in order to facilitate thepurification, it is usually preferred to conduct the reaction in theabsence of a solvent.

The amount of the catalyst varies depending upon the type of thecatalyst used. However, it is usually from 0.01 to 50% by weight,preferably from 0.1 to 10% by weight, relative to the starting material.The reaction is conducted usually within a temparature range of from-80° to 200° C., preferably from -20° to 100° C. The reaction pressureis usually from 0 to 30 kg/cm².G, preferably from 0 to 15 kg/cm².G.

The amount of tetrafluoroethylene to be added is usually preferably atleast equimolar to R21 to increase the conversion of R21.

If the addition reaction of R21 to tetrafluoroethylene (4F) in thepresence of a Lewis acid catalyst is conducted under such reactioncondition that the molar ratio of 4F to R21 is at least equimolar,preferably in an excess amount, the disproportionation reaction of R21is substantially suppressed, whereby as shown by the following formula:##STR3## 3,3-dichloro-1,1,1,2,2-pentafluoropropane (R225ca) and1,3-dichloro-1,1,2,2,3-pentafluoropropane (R225cb) can be obtained ingood yield, and chloroform produced in a small amount as a by-product bythe disproportionation, will react with tetrafluoroethylene present inan excess amount to give 1,3,3-trichloro-1,1,2,2-tetrafluoropropane(R224ca) as shown by the following formula: ##STR4## R224ca has aboiling point different from R225 and can easily be separated bydistillation.

The amount of tetrafluoroethylene to be added is preferably at leastequimolar to R21, although it may depend also on the amount of the Lewisacid. Preferably, the molar ratio of 4F to R21 is 1.01≦4F/R21≦10,particularly 1.01≦4F/R21≦5, more preferably 1.1≦4F/R21≦3. The manner ofsupplying tetrafluoroethylene (4F) and dichlorofluoromethane (R21) isnot particularly limited so long as the reaction condition is eventuallysuch that 4F is present in an equimolar amount, preferably in an excessamount, to R21. However, in order to suppress the disproportionationreaction of R21, it is preferred to supply them continuously to thereactor while maintaining the molar ratio in supply of 4F to R21 withina range of 1≦4F/R21, preferably 1.01≦4F/R21≦10, particularly1.01≦4F/R21≦5, more preferably 1.1≦4F/R21≦3, and to withdraw thereaction product containing R225 from the reactor continuously. Theexcess amount of 4F can be recovered after the reaction. Therefore, 4Fcan be used in large excess at a level of 10 mol times or more, but itis not an economical operation.

The Lewis acid catalyst may be supplied preliminarily to the reactor, orit may be supplied continuously to the reactor together with 4F and R21and withdrawn continuously from the reactor together with the reactionproduct. In the latter case, the recovered Lewis acid catalyst can berecycled.

If R21 remains in the reaction product, dispropornation takes place toform by-products such as chloroform. Therefore, in order to improve theselectivity for the desired reaction, it is always preferred to controlthe concentration of R21 to the minimum level. To minimize theconcentration of R21 in the reactor, it is preferred to supply thestarting materials R21 and 4F (and the catalyst) continuously to thereactor and to withdraw the reaction product continuously, so that theconcentrations of the respective components can be maintained atconstant levels, and if 4F is used in excess, it is possible to suppressthe concentration of R21 to the minimum level. Thus, such an operationis preferred.

The reactor to be used for the continuous operation may be any so-calledcontinuous reactor and may be of either continuous stirred tank reactoror plug flow reactor.

Further, it is necessary to feed solvent for the reaction at theinitiation of the reaction. However, in the case of a continuousoperation, as the reaction continuously proceeds, the solvent forreaction will gradually be replaced by the reaction product. Therefore,the solvent for reaction is not particularly restricted, so long as itdoes not adversely affect the main reaction.

As for the solvent at the initiation of the reaction, it is preferred toemploy PFC such as perfluorooctane or perfluorobutyltetrahydrofuran, CFCsuch as 1,1,1-trichloropentafluoropropane (R215cb),1,1,3-trichloropentafluoropropane (R215ca) or1,1,1,3-tetrachlorotetrafluoropropane (R214cb), or HCFC such as3,3-dichloro-1,1,1,2,2-pentafluoropropane (R225ca),1,3-dichloro-1,1,2,2,3-pentafluoropropane (R225cb) or 1,3,3-trichloro-1,1,2,2-tetrafluoropropane (R224ca). However, it is possible to conductthe reaction without solvent. The reaction is conducted usually within atemperature range of from -80° to 200° C., preferably from -20° to 100°C. The reaction pressure is usually from 0 to 20 kg/cm², preferably from0 to 10 kg/cm².

In the case of a continuous operation, the resident time of the reactionsolution is usually from 0.1 minute to 24 hours, preferably from 1minute to 10 hours, although it depends on the reaction temperatures andthe type of the Lewis acid catalyst used.

The amount of the Lewis acid catalyst is usually from 0.1 to 50 mol%,preferably from 0.1 to 10 mol%, relative to R21. The catalyst to be usedfor this reaction is not particularly restricted so long as it is aLewis acid. However, it is preferred to employ a halide containing atleast one element selected from the group consisting of Al, Sb, Nb, Ta,B, Ga, In, Zr, Hf and Ti. For example, it is possible to employchlorides such as GaCl₂, GaCl₃, ZrCl₄, BCl₃, AlCl₃, HfCl₄, InCl₃ andTiCl₄, or partially fluorinated compounds thereof, or bromides andiodides such as GaBr₃, GaI₃, HfBr₄, HfI₄, InBr₃, InI₃, and TiBr₄, orpartially chlorinated or fluorinated compounds thereof, such as TiCl₂F₂, TiCl_(F) ₃, and ZrCl₂ F₂.

Further, chlorides such as SbCl₅, NbCl₅, TaCl₅, BCl₃ and partiallyfluorinated compounds thereof, fluorides such as SbF₅, NbF₅, TaF₅, andBF₃ are partially chlorinated compounds thereof, and bromides andiodides such as TaBr₅, AlBr₃, BBR₃ and BI₃ and partially chlorinated orfluorinated compounds thereof, may be used.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

Now, the present invention will be described in further detail withreference to Examples. However, it should be understood that the presentinvention is by no means restricted by such specific Examples.

EXAMPLE 1

Into a 200 ml Hastelloy C autoclave, 2 g of antimony pentachloride wasadded and cooled to -78° C. Then, the autoclave was deaerated unerreduced pressure, and 155 g (1.5 mol) of R21 was added thereto. Aftercharging 20 g of tetrafluoroethylene, the temperature was raised to 30°C., and tetrafluoroethylene was continuously added with stirring. Twelvehours later, the supply of tetrafluoroethylene was stopped, and stirringwas continued for further 4 hours. The total amount oftetrafluoroethylene charged was 150 g. The pressure was returned tonormal pressure, and then the reaction solution was washed with water,and about 220 g of the crude reaction product was recovered. The resultsof the analyses by means of gas chromatography and NMR are shown inTable 1.

                  TABLE 1                                                         ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225            81                                                            Chloroform       1                                                            Other components                                                                              18                                                            ______________________________________                                    

EXAMPLE 2

The reaction was conducted in the same manner as in Exampel 1 exceptthat 2 g of niobium pentachloride was used instead of antimonypentachloride, whereby 190 g of the crude reaction product wasrecovered. The results of the analyses by means of gas chromatographyand NMR are shown in Table 2.

                  TABLE 2                                                         ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225            85                                                            Chloroform       2                                                            Other components                                                                              13                                                            ______________________________________                                    

EXAMPLE 3

The reaction was conducted in the same manner in Example 1 except that 2g of tantalum pentachloride was used instead of antimony pentachloride,whereby 190 g of the crude reaction product was recovered. The resultsof the analyses by means of gas chromatography and NMR are shown inTable 3.

                  TABLE 3                                                         ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225            84                                                            Chloroform       2                                                            Other components                                                                              14                                                            ______________________________________                                    

EXAMPLE 4

The reaction was conducted in the same manner as in Example 1 exceptthat 2 g of aluminum bromide was used instead of antimony pentachlorideand the reaction temperature was changed to -10° C., whereby 240 g ofthe crude reaction product was recovered. The results of the analyses bymeans of gas chromatography and NMR are shown in Table 4.

                  TABLE 4                                                         ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225            77                                                            Chloroform       1                                                            Other components                                                                              22                                                            ______________________________________                                    

EXAMPLE 5

The reaction was conducted in the same manner as in Example 1 exceptthat 2 g of aluminum iodide was used instead of antimony pentachlorideand the reaction temperature was changed to -10° C., whereby 240 g ofthe crude reaction product was recovered. The results of the analyses bymeans of gas chromatography and NMR are shown in Table 5.

                  TABLE 5                                                         ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225            83                                                            Chloroform       2                                                            Other components                                                                              15                                                            ______________________________________                                    

EXAMPLE 6

Into a 200 ml Hastelloy C autoclave, 2 g (0.009 mol) of zirconium(IV)chloride was added and cooled to -78° C. Then, the autoclave wasdeaerated and 155 g (1.5 mol) of R21 was added thereto. After charging20 g of tetrafluoroethylene, the temperature was raised to 10° C., andtetrafluoroethylene was continuously added while maintaining thereaction temperature within a range of from 10° to 20° C. Twelve hourslater, the supply of tetrafluoroethylene was stopped, and stirring wascontinued for further 4 hours. The total amount of tetrafluoroethylenecharged was 150 g. The pressure was returned to normal pressure, andthen the reaction solution was washed with water, and 260 g of the crudereaction product was recovered. The results of the analyses by means ofgas chromatography and NMR are shown in Table 6.

                  TABLE 6                                                         ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225ca          39                                                            R225cb          42                                                            Chloroform       1                                                            R224ca          15                                                            (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components                                                                               3                                                            ______________________________________                                    

EXAMPLE 7

The reaction was conducted in the same manner as in Example 6 exceptthat 2 g of titanium tetrachloride was used instead of zirconium(IV)chloride, whereby 190 g of the crude reaction product was recovered. Theresults of the analyses by means of gas chromatography and NMR are shownin Table 7.

                  TABLE 7                                                         ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225ca          37                                                            R225cb          43                                                            Chloroform       5                                                            R224ca          10                                                            (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components                                                                               5                                                            ______________________________________                                    

EXAMPLE 8

The reaction was conducted in the same manner as in Example 6 exceptthat 2 g of gallium trichloride was used instead of zirconium(IV)chloride, whereby 190 g of the crude reaction product was recovered. Theresults of the analyses by means of gas chromatography and NMR are shownin Table 8.

                  TABLE 8                                                         ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225ca          40                                                            R225cb          30                                                            Chloroform       3                                                            R224ca          16                                                            (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components                                                                              11                                                            ______________________________________                                    

EXAMPLE 9

The reaction was conducted in the same manner as in Example 6 exceptthat 2 g of hafnium tetrachloride was used instead of zirconium(IV)chloride and the reaction temperature was changed to from 10° to 20° C.,whereby 240 g of the crude reaction product was recovered. The resultsof the analyses by means of gas chromatography and NMR are shown inTable 9.

                  TABLE 9                                                         ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225ca          38                                                            R225cb          41                                                            Chloroform       2                                                            R224ca          11                                                            (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components                                                                               8                                                            ______________________________________                                    

EXAMPLE 10

The reaction was conducted in the same manner as in Example 6 exceptthat 2 g of zirconium dichloride difluoride was used instead ofzirconium(IV) chloride, whereby about 260 g of the crude reactionproduct was recovered. The results of the analyses by means of gaschromatography and NMR are shown in Table 10.

                  TABLE 10                                                        ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225ca          36                                                            R225cb          54                                                            Chloroform       1                                                            R224ca           6                                                            (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components                                                                               3                                                            ______________________________________                                    

EXAMPLE 11

The reaction was conducted in the same manner as in Example 6 exceptthat 2 g of titanium dichloride difluoride was used instead ofzirconium(IV) chloride, whereby about 260 g of the crude reactionproduct was recovered. The results of the analyses by means of gaschromatography and NMR are shown in Table 11.

                  TABLE 11                                                        ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225ca          37                                                            R225cb          53                                                            Chloroform       1                                                            R224ca           7                                                            (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components                                                                               2                                                            ______________________________________                                    

COMPARATIVE EXAMPLE 1-I

Into a 200 ml Hastelloy C autoclave, 3 g (0.02 mol) of anhydrousaluminum chloride was added and cooled to -78° C. Then, the autoclavewas deaerated, and 155 g (1.5 mol) of R21 was added thereto. Thetemperature was raised to 10° C., and tetrafluoroethylene wascontinuously added while maintaining the reaction temperature within arange of from 10° to 20° C. Twelve hours later, the supply oftetrafluoroethylene was stopped, and stirring was continued for further4 hours. The total amount of tetrafluoroethylene charged was 120 g. Thepressure was returned to normal pressure, and then the reaction solutionwas washed with water, and about 200 g of the crude reaction product wasrecovered. The results of the analyses by means of gas chromatographyand NMR are shown in Table 1-I.

                  TABLE 1-I                                                       ______________________________________                                        Reaction product                                                                              Molar ratio (%)                                               ______________________________________                                        R225ca          27                                                            R225cb          18                                                            Chloroform      20                                                            R224ca          10                                                            (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components                                                                              25                                                            ______________________________________                                    

PREPARATION EXAMPLE 1

Into a 2 l three necked round bottom flask equipped with a refluxcondenser, 200 g (1.5 mol) of anhydrous aluminum chloride and 2000 g(14.6 mol) of trichlorofluoromethane (R11) were charged under a nitrogenstream and generally stirred at 0° C. for 12 hours. After leaving thereaction mixture to stand still for 1 hour, the supernatant was removed,followed by drying under reduced pressure to obtain AlCl₃₋β F.sub.β. Thefluorine content β of this product was 0.1.

PREPARATION EXAMPLE 2

Into a 2 l three necked and round bottom flask equipped with a refluxcondenser, 200 g (0.86 mol) of anhydrous zirconium(IV) chloride and 200g (14.6 mol) of trichlorofluoromethane (R11) were charged under anitrogen stream and stirred at 0° C. for 2 hours. After leaving themixture to stand still for 1 hour, the supernatant was removed, followedby drying under reduced pressure to obtain ZrCl₄₋β F.sub.β. The fluorinecontent β of this product was 1.6.

PREPARATION EXAMPLE 3

Into a 2 l three necked round bottom flask equipped with a refluxcondenser, 200 g (1.1 mol) of anhydrous titanium tetrachloride and 2000g (19.4 mol) of dichlorofluoromethane (R21) were charged under anitrogen stream and stirred at 0° C. for 12 hours. After leaving themixture to stand still for 1 hour, the supernatant was removed, followedby drying under reduced pressure to obtain TiCl₄₋β F.sub.β. The fluorinecontent β of this product was 2.3.

PREPARATION EXAMPLE 4

Into a 1 l Hastelloy C autoclave, 200 g (0,6 mol) of anhydrous tantalumpentachloride was charged, and the autoclave was deaerated under reducedpressure. Then, 500 g (25 mol) of anhydrous hydrogen fluoride was addedthereto, and the mixture was stirred at 50° C. for 5 hours. Then,hydrogen fluoride and hydrogen chloride were removed under reducedpressure to obtain TaCl₅₋β F.sub.β. The fluorine content β of thisproduct was 4.

EXAMPLE 12

Into a 10 l Hastelloy C autoclave, 0.1 kg of aluminum fluoride chlorideprepared in Preparation Example 1 was charged, and the autoclave wasdeaerated under reduced pressure. Then, 3 kg (14. 8 mol) of R225ca (CF₃CF₂ CHCl₂) was added thereto. The autoclave was cooled to -10° C. Then,while maintaining the reaction temperature within a range of from 0° to5° C., tetrafluoroethylene and R21 were continuously added at the ratesof 850 g/hr and 670 g/hr, respectively. Six hours later, the supply oftetrafluoroethylene and R21 was stopped, and stirring was continued forfurther 4 hours while maintaining the reaction temperature within arange of from 5° to 10° C. The pressure was returned to normal pressure,and then the reaction solution was subjected to filtration, wherebyabout 10.7 kg of the crude reaction product was recovered. The resultsof the analyses by means of gas chromatography and ¹⁹ F-NMR are shown inTable 12. The crude reaction product was purified by distillation toobtained 9.8 kg of R225 (dichloropentafluoropropane).

                  TABLE 12                                                        ______________________________________                                        Composition of the                                                            reaction solution                                                                             Molar ratio (%)                                               ______________________________________                                        R225ca          71.5                                                          (CF.sub.3 CF.sub.2 CHCl.sub.2)                                                R225cb          23                                                            (CClF.sub.2 CF.sub.2 CHClF)                                                   Chloroform      0                                                             (CHCl.sub.3)                                                                  R224ca          2                                                             (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components                                                                              3.5                                                           ______________________________________                                    

EXAMPLE 13

The reaction was conducted in the same manner as in Preparation Example1 except that 200 g (19.4 mol) of dichlorofluoromethane (R21) was usedinstead of trichlorofluoromethane (R11), to obtain aluminum fluoridechloride (β: 0.01). Then, using 0.1 kg of this product, the reaction wasconducted in the same manner as in Example 12, whereby 10.8 kg of thecrude reaction product was recovered. The results of the analyses bymeans of gas chromatography and NMR are shown in Table 13. The crudereaction product was purified by distillation to obtain 9.6 kg of R225(dichloropentafluoropropane).

EXAMPLE 14

The reaction was conducted in the same manner as in Example 12 exceptthat 0.1 kg of zirconium fluoride chloride obtained in PreparationExample 2 was used, whereby 10.8 kg of the crude reaction product wasrecovered. The results of the analyses by means of gas chromatographyand NMR are shown in Table 13. The reaction product was purified bydistillation to obtain 10.2 kg of R225 (dichloropentafluoropropane).

EXAMPLE 15

The reaction was conducted in the same manner as in Preparation Example2 except that 2000 g (19.4 mol) of dichlorofluoromethane (R21) was usedinstead of trichlorofluoromethane (R11), whereby zirconium fluoridechloride was prepared (β:1.8). Then, using 0.1 kg of this product, thereaction was conducted in the same manner as in Example 12, whereby 10.7kg of the crude reaction product was recovered. The results of theanalyses by means of gas chromatography and NMR are shown in Table 13.The crude reaction product was purified by distillation to obtain 10.1kg of R225 (dichloropentafluoropropane).

EXAMPLE 16

The reaction was conducted in the same manner as in Example 12 exceptthat 0.2 kg of tantalum fluoride chloride prepared in PreparationExample 4 was used, whereby 9.5 kg of the crude reaction product wasrecovered. The results of the analyses by means of gas chromatographyand NMR are shown in Table 13. The crude reaction product was purifiedby distillation to obtain 8.5 kg of R225 (dichloropentafluoropropane).

                  TABLE 13                                                        ______________________________________                                        Composition of the                                                                           Example Nos.                                                   reaction products (%)                                                                        13    14        15   16                                        ______________________________________                                        R225ca         72    58        58   65                                        R225cb         22    40        41   23                                        Chloroform      0    0         0    1                                         R224ca          2    1.5       0.5  6.5                                       Others          4    0.5       0.5  4.5                                       ______________________________________                                    

EXAMPLE 17

The reaction was conducted in the same manner as in Example 12 exceptthat 0.1 kg of titanium fluoride chloride prepared in PreparationExample 3 was used, whereby 10.5 kg of the crude reaction product wasrecovered. The results of the analyses by means of gas chromatographyand NMR are shown in Table 14. The crude reaction product was purifiedby distillation to obtain 9.5 kg of R225 (dichloropentafluoropropane).

EXAMPLE 18

The reaction was conducted in the same manner as in Preparation Example3 except that 2000 g (14.6 mol) of trichlorofluoromethane (R11) was usedinstead of dichlorofluoromethane (R21) and stirring was conducted at 10°C. for one week, whereby titanium fluoride chloride was prepared(β:2.2). Then, using 0.1 kg of this product, the reaction was conductedin the same manner as in Example 12, whereby 10.7 kg of the crudereaction product was recovered. The results of the analyses by means ofgas chromatography and NMR are shown in Table 14. The crude reactionproduct was purified by distillation to obtain 9.6 kg of R225(dichloropentafluoropropane).

EXAMPLE 19

The reaction was conducted in the same manner as in Preparation Example1 except that 200 g of hafnium tetrachloride was used instead ofzirconium(IV) chloride, whereby hafnium fluoride chloride (β:1,5) wasprepared. Then, using 0.1 kg of this product, the reaction was conductedin the same manner as in Example 12, whereby 10.7 kg of the crudereaction product was recovered. The results of the analyses by means ofgas chromatography and NMR are shown in Table 14. The crude reactionproduct was purified by distillation to obtain 9.9 kg of R225(dichloropentafluoropropane).

EXAMPLE 20

The reaction was conducted in the same manner as in Preparation Example2 except that 200 g of hafnium tetrachloride was used instead ofzirconium(IV) chloride, 2000 g (19.4 mol) of dichlorofluoromethane (R21)was used instead of trichlorofluoromethane (R11), whereby hafniumfluoride chloride (β:1.7) was prepared. Then, using 0.1 kg of thisproduct, the reaction was conducted in the same manner as in Example 12,whereby 10.6 kg of the crude reaction product was recovered. The resultsof the analyses by means of gas chromatography and NMR are shown inTable 14. The crude reaction product was purified by distillation toobtain 9.8 kg of R225 (dichloropentafluoropropane).

                  TABLE 14                                                        ______________________________________                                        Composition of the                                                                           Example Nos.                                                   reaction solution (%)                                                                        17     18       19   20                                        ______________________________________                                        R225ca         60     61       60   59                                        R225cb         37     36       38   39                                        Chloroform     0      0        0    0                                         R224ca         2.5    2.5      1.5  1.5                                       Others         0.5    0.5      0.5  0.5                                       ______________________________________                                    

EXAMPLE 21

A 10 l Hastelloy C autoclave was deaerated under reduced pressure after100 g of aluminum fluoride chloride prepared in Preparation Example 1was charged. And then, 10 kg of 1,1,1-trichloropentafluoropropane(R215cb) was charged as an initial solvent. The autoclave was cooled to-10° C. Then, while maintaining the reaction temperature within a rangeof from 0° to 5° C., tetrafluoroethylene, dichlorofluoromethane and thealuminum fluoride chloride prepared in Preparation Example 1 werecontinuously added at the rate of 1300 g/hr, 1030 g/hr and 20 g/hr,respectively. The reaction was conducted with continuously dischargingthe reaction mixture which is the same amount as the charged one. Fromthe results of the analyses by means of gas chromatography and ¹⁹ F-NMR,it was found that after 20 hours of the reaction, the initial solventR215cb was not present in the reaction mixture. The composition of thereaction products after 30 hours is shown in Table 15. 10.7 kg of thecrude reaction products recovered since 20 hours later was purified bydistillation to obtain 9.2 kg (yield: 86%) of dichloropentafluoropropane(R225).

EXAMPLE 22

The reaction was conducted in the same manner as in Example 21 exceptthat zirconium fluoride chloride prepared in Preparation Example 2 wasused instead of aluminum fluoride chloride. The composition of thereaction products after 30 hours of the reaction is shown in Table 15.10.7 kg of a crude reaction products recovered since 20 hours later waspurified by distillation to obtain 9.2 kg (yield: 86%) ofdichloropentafluoropropane (R225).

EXAMPLE 23

The reaction was conducted in the same manner as in Example 21 exceptthat 40 g/hr of titanium fluoride chloride prepared in PreparationExample 3 was supplied instead of aluminum fluoride chloride. Thecomposition of the reaction products after 30 hours of the reaction isshown in Table 15. 10.7 kg of the crude reaction products recoveredsince 20 hours later was purified by distillation to obtain 9.2 kg(yield: 86%) of dichloropentafluoropropane (R225).

EXAMPLE 24

The reaction was conducted in the same manner as in Example 21 exceptthat hafnium fluoride chloride was in Example 19 was employed instead ofaluminum fluoride chloride. The composition of the reaction productsafter 30 hours of the reaction is shown in Table 15. 10.7 kg of thecrude reaction products recovered since 20 hours later was purified bydistillation to obtain 9.2 kg (yield: 86%) of dichloropentafluoropropane(R225).

EXAMPLE 25

The reaction was conducted in the same manner as in Example 21 exceptthat 40 g/hr of tantalum fluoride chloride prepared in PreparationExample 4 was used instead of aluminum fluoride chloride. Thecomposition of the reaction products after 30 hours is shown in Table15. 10.7 kg of the crude reaction product recovered after 20 hours waspurified by distillation to obtain 9 kg (yield: 84%) ofdichloropentafluoropropane (R225).

                  TABLE 15                                                        ______________________________________                                        Composition of the                                                                           Example Nos.                                                   reaction solution (%)                                                                        21      22    23     24  25                                    ______________________________________                                        R225ca         58      40    39     40  60                                    R225cb         38      58    57     58  35                                    Chloroform      0       0     0      0   0                                    R224ca          2       1     3      1   3                                    Others          2       1     1      1   2                                    ______________________________________                                    

EXAMPLE 26

The reaction was conducted in the same manner as in Example 12 exceptthat 0.1 kg of anhydrous aluminum chloride was used instead of aluminumfluoride chloride, whereby 10.7 kg of the crude reaction product wasrecovered. The results of the analyses by means of gas chromatographyand NMR are shown in Table 16. The crude reaction product was purifiedby distillation to obtain 9.1 kg of R225 (dichloropentafluoropropane).

EXAMPLE 27

The reaction was conducted in the same manner as in Example 14 exceptthat anhydrous zirconium(IV) chloride was used instead of zirconium(IV)fluoride chloride, whereby 10.7 kg of the crude reaction product wasrecovered. The results of the analyses by means of gas chromatographyand NMR are shown in Table 16. The crude reaction product was purifiedby distillation to obtain 9 kg of R225 (dichloropentafluoropropane).

EXAMPLE 28

The reaction was conducted in the same manner as in Example 17 exceptthat 0.1 kg of anhydrous titanium chloride was used instead of titaniumfluoride chloride, whereby 10.5 kg of the crude reaction product wasrecovered. The results of the analyses by means of gas chromatographyand NMR are shown in Table 16. The crude reaction product was purifiedby distillation to obtain 8.5 kg of R225 (dichloropentafluoropropane).

EXAMPLE 29

The reaction was conducted in the same manner as in Example 19 exceptthat 0.1 kg of anhydrous hafnium tetrachloride was used instead ofhafnium fluoride chloride, whereby 10.5 kg of a crude reaction productswas recovered. The results of the analyses by means of gaschromatography and NMR are shown in Table 16. The crude reaction productwas purified by distillation to obtain 8.9 kg of R225(dichloropentafluoropropane).

EXAMPLE 30

The reaction was conducted in the same manner as in Example 16 exceptthat 0.1 kg of anhydrous tantalum pentachloride was used instead oftantalum fluoride chloride, whereby 9 kg of the crude reaction productwas recovered. The results of the analyses by means of gaschromatography and NMR are shown in Table 16. The crude reaction productwas purified by distillation to obtain 7.5 kg of R225(dichloropentafluoropropane).

                  TABLE 16                                                        ______________________________________                                        Composition of the                                                                           Example Nos.                                                   reaction solution (%)                                                                        26      27     28    29   30                                   ______________________________________                                        R225ca         71      58     59    59   64                                   R225cb         22      40     37    38   22                                   Chloroform     0.5     0.5    1     0.5   2                                   R224ca         2       1      2.5   1.5   8                                   Others         4.5     0.5    0.5   1     4                                   ______________________________________                                    

EXAMPLE 31

The reaction was conducted in the same manner as in Example 12 exceptthat 3 kg (12.6 mol) of R215cb (CF₃ CF₂ CCl₃) was used instead of R225caas the solvent for reaction and anhydrous aluminum chloride was used,whereby 10.5 kg of the crude reaction product was recovered. The resultsof the analyses by means of gas chromatography and ¹⁹ F-NMR are shown inTable 17.

                  TABLE 17                                                        ______________________________________                                        Composition of the  Molar                                                     reaction solution   ratio (%)                                                 ______________________________________                                        R225                                                                          CF.sub.3 CF.sub.2 CHCl.sub.2                                                                 (R225ca) 45                                                    CClF.sub.2 CF.sub.2 CHClF                                                                    (R225cb) 23                                                    R224b                                                                         CClF.sub.2 CF.sub.2 CHCl.sub.2                                                               (R224ca)  2                                                    CHCl.sub.3     (R20)     0                                                    R215                                                                          CF.sub.3 CF.sub.2 CCl.sub.3                                                                  (R215cb) 24                                                    Other components         6                                                    ______________________________________                                    

The crude reaction solution was purified by distillation to obtain 6.6kg (yield: 84%) of R225 (dichloropentafluoropropane).

EXAMPLE 32

Into a 10 l Hastelloy C autoclave, 0.2 kg (1.5 mol) of anhydrousaluminum chloride was charged, and the autoclave was deaerated underreduced pressure. Then, autoclave was cooled to -10° C., and 5 kg (48.6mol) of R21 (CHCl₂ F) was added thereto. Then, while maintaining thereaction temperature within a range of from 0° to 5° C.,tetrafluoroethylene was continuously added at the rate of 800 g/hr. Theupper limit of the reaction pressure was 5 kg/cm², and the reaction wascontinued while purging the gas as the case required. Five hours later,the reaction temperature was raised to 20° C., and the reaction wascontinued with further supply of tetrafluoroethylene. When chloroform inthe system was consumed, the reaction was stopped, and the pressure wasreturned to normal pressure. Then, the reaction solution was subjectedto filtration, whereby 7.8 kg of the crude reaction product wasrecovered. The results of the analyses by means of gas chromatographyand ¹⁹ F-NMR are shown in Table 18.

                  TABLE 18                                                        ______________________________________                                        Composition of the  Molar                                                     reaction solution   ratio (%)                                                 ______________________________________                                        R225                                                                          CF.sub.3 CF.sub.2 CHCl.sub.2                                                                 (R225ca) 37                                                    CClF.sub.2 CF.sub.2 CHClF                                                                    (R225cb) 10                                                    R224                                                                          CClF.sub.2 CF.sub.2 CHCl.sub.2                                                               (R224ca) 36                                                    Other components        17                                                    ______________________________________                                    

The crude reaction product was purified by distillation to obtain 3.5 kg(yield: 35%) of R225 (dichloropentafluoropropane).

EXAMPLE 33

A 10 l Hastelloy C autoclave was deaerated under reduced pressure. Then,10 kg of R215cb (Cf₃ CF₂ CCl₃) was charged as the initial solvent.

The autoclave was cooled to -15° C. Then, while maintaining the reactiontemperature within a range of from -10° C. to -5° C.,tetrafluoroethylene, R21 and aluminum chloride were continuously addedat the rates of 11300 g/hr, 1030 g/hr and 20 g/hr (1.5 mol% relative toR21, same applied hereinafter), respectively. The reaction was conductedwith continuously withdrawing the reaction mixture which is the sameamount as the charged one. From the results of the analyses by means ofgas chromatography and ¹⁹ F-NMR, it was found that after 20 hours of thereaction, the initial solvent R215cb was not present in the reactionmixture. The composition of the reaction solution at that time is shownin Table 19.

                  TABLE 19                                                        ______________________________________                                        Composition of the  Molar                                                     reaction solution   ratio (%)                                                 ______________________________________                                        R225                                                                          CF.sub.3 CF.sub.2 CHCl.sub.2                                                                 (R225ca) 57                                                    CClF.sub.2 CF.sub.2 CHClF                                                                    (R225cb) 37                                                    R224                                                                          CClF.sub.2 CF.sub.2 CHCl.sub.2                                                               (R224ca)  3                                                    CHCl.sub.3     (R20)     0                                                    Other components         3                                                    ______________________________________                                    

The reaction mixture which is the same amount as the charged one wascontinuously withdrawn, and 10.7 kg of the crude reaction productthereby obtained was purified by distillation to obtain 9.1 kg (yield:85%) of R225 (dichloropentafluoropropane).

EXAMPLE 34

The reaction was conducted in the same manner as in Example 33 exceptthat the supplying rates of tetrafluoroethylene, R21 and aluminumchloride were doubled by twice, whereby 10.5 kg of the crude reactionproduct was recovered. The results of the analyses by means of gaschromatography and ¹⁹ F-NMR are shown in Table 20.

                  TABLE 20                                                        ______________________________________                                        Composition of the  Molar                                                     reaction solution   ratio (%)                                                 ______________________________________                                        R225                                                                          CF.sub.3 CF.sub.2 CHCl.sub.2                                                                 (R225ca) 55                                                    CClF.sub.2 CF.sub.2 CHClF                                                                    (R225cb) 36                                                    R224                                                                          CClF.sub.2 CF.sub.2 CHCl.sub.2                                                               (R224ca)  5                                                    CHCl.sub.3     (R20)     0                                                    Other components         4                                                    ______________________________________                                    

The crude reaction product was purified by distillation to obtain 8.8 kg(yield: 84%) of R225 (dichloropentafluoropropane).

EXAMPLE 35

The reaction was conduced in the same manner as in Example 33 exceptthat the supplying rate of aluminum chloride was changed to 67 g/hr (5.5mol%), whereby 9.8 kg of the crude reaction product was recovered. Theresults of the analyses by means of gas chromatography and ¹⁹ F-NMR areshown in Table 21.

                  TABLE 21                                                        ______________________________________                                        Composition of the  Molar                                                     reaction solution   ratio (%)                                                 ______________________________________                                        R225                                                                          CF.sub.3 CF.sub.2 CHCl.sub.2                                                                 (R225ca) 53                                                    CClF.sub.2 CF.sub.2 CHClF                                                                    (R225cb) 37                                                    R224                                                                          CClF.sub.2 CF.sub.2 CHCl.sub.2                                                               (R224ca)  5                                                    CHCl.sub.3     (R20)     1                                                    Other c omponents        4                                                    ______________________________________                                    

The crude reaction product was purified by distillation to obtain 8.0 kg(yield: 82%) of R225 (dichloropentafluoropropane).

EXAMPLE 36

The reaction was conducted in the same manner as in Example 26 exceptthat the reaction temperature was changed in the range of 0° to 5° C.,whereby 8.5 kg of the crude reaction product was recovered. The resultsof the analyses by means of gas chromatography and ¹⁹ F-NMR are shown inTable 22.

                  TABLE 22                                                        ______________________________________                                        Composition of the  Molar                                                     reaction solution   ratio (%)                                                 ______________________________________                                        R225                                                                          CF.sub.3 CF.sub.2 CHCl.sub.2                                                                 (R225ca) 52                                                    CClF.sub.2 CF.sub.2 CHClF                                                                    (R225cb) 36                                                    R224                                                                          CClF.sub.2 CF.sub.2 CHCl.sub.2                                                               (R224ca)  5                                                    CHCl.sub.3     (R20)     0                                                    Other components         7                                                    ______________________________________                                    

The crude reaction product was purified by distillation to obtain 6.8 kg(yield: 80%) of R225 (dichloropentafluoropropane).

EXAMPLE 37

The reaction was conducted in the same manner as in Example 33 exceptthat the catalyst was changed to zirconium(IV) chloride, and thesupplying rate of the catalyst was changed to 20 g/hr (0.9 mol%),whereby 11 kg of the crude reaction solution was recovered. The resultsof the analyses by means of gas chromatography and NMR are shown inTable 23.

                  TABLE 23                                                        ______________________________________                                        Composition of the                                                                             Molar                                                        reaction solution                                                                              ratio (%)                                                    ______________________________________                                        R225ca           39                                                           R225cb           58                                                           Chloroform        0                                                           R224              2                                                           (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components  1                                                           ______________________________________                                    

The crude reaction solution was purified by distillation to obtain 9.5kg (yield: 86%) of R225 (dichloropentafluoropropane).

EXAMPLE 38

The reaction was conducted in the same manner as in Example 33 exceptthat the catalyst was changed to titanium tetrachloride, and thesupplying rate of the catalyst was changed to 20 g/hr (1.1 mol%),whereby 11 kg of the crude reaction solution was recovered. The resultsof the analyses by means of gas chromatography and NMR are shown inTable 24.

                  TABLE 24                                                        ______________________________________                                        Composition of the                                                                             Molar                                                        reaction solution                                                                              ratio (%)                                                    ______________________________________                                        R225ca           38                                                           R225cb           56                                                           Chloroform        0                                                           R224ca            4                                                           Other components  2                                                           ______________________________________                                    

The crude reaction solution was purified by distillation to obtain 9.2kg (yield: 84%) of R225 (dichloropentafluoropropane).

EXAMPLE 39

The reaction was conducted in the same manner as in Example 33 exceptthat the catalyst was changed to zirconium dichloride difluoride, andthe supplying rate of the catalyst was changed to 20 g/hr (1 mol%),whereby 11 kg of the crude reaction product was recovered. The resultsof the analyses by means of gas chromatography and NMR are shown inTable 25.

                  TABLE 25                                                        ______________________________________                                        Composition of the                                                                             Molar                                                        reaction solution                                                                              ratio (%)                                                    ______________________________________                                        R225ca           39                                                           R225cb           58                                                           Chloroform        0                                                           R224ca            2                                                           (CClF.sub.2 CF.sub.2 CHCl.sub.2)                                              Other components  1                                                           ______________________________________                                    

The crude reaction product was purified by distillation to obtain 9.5 kg(yield: 86%) of R225 (dichloropentafluoropropane).

EXAMPLE 40

The reaction was conducted in the same manner as in Example 33 exceptthat the catalyst was changed to titanium chloride difluoride, and thesupplying rate of the catalyst was changed to 20 g/hr (1.3 mol%),whereby 11 kg of the crude reaction solution was recovered. The resultsof the analyses by means of gas chromatography and NMR are shown inTable 26.

                  TABLE 26                                                        ______________________________________                                        Composition of the                                                                             Molar                                                        reaction solution                                                                              ratio (%)                                                    ______________________________________                                        R225ca           38                                                           R225cb           56                                                           Chloroform        0                                                           R224ca            4                                                           Other components  2                                                           ______________________________________                                    

The crude reaction solution was purified by distillation to obtain 9.2kg (yield: 84%) of R225 (dichloropentafluoropropane).

EXAMPLE 41

The reaction was conducted in the same manner as in Example 33 exceptthat the catalyst was changed to gallium trichloride, and the supplyingrate of the catalyst was changed to 20 g/hr (1.1 mol%), whereby 11 kg ofa crude reaction solution was recovered. The results of the analyses bymeans of gas chromatography and NMR are shown in Table 27.

                  TABLE 27                                                        ______________________________________                                        Composition of the                                                                             Molar                                                        reaction solution                                                                              ratio (%)                                                    ______________________________________                                        R225ca           40                                                           R225cb           50                                                           Chloroform        1                                                           R224ca            7                                                           Other components  2                                                           ______________________________________                                    

The crude reaction solution was purified by distillation to obtain 9 kg(yield: 81%) of R225 (dichloropentafluoropropane).

EXAMPLE 42

The reaction was conducted in the same manner as in Example 33 exceptthat the catalyst was changed to hafnium tetrachloride, and thesupplying rate of the catalyst was changed to 20 g/hr (0.6 mol%),whereby 11 kg of the crude reaction solution was recovered. The resultsof the analyses by means of gas chromatography and NMR are shown inTable 28.

                  TABLE 28                                                        ______________________________________                                        Composition of the                                                                             Molar                                                        reaction solution                                                                              ratio (%)                                                    ______________________________________                                        R225ca           38                                                           R225cb           57                                                           Chloroform        0                                                           R224ca            3                                                           Other components  2                                                           ______________________________________                                    

The crude reaction solution was purified by distillation to obtain 9.5kg (yield: 86%) of R225 (dichloropentafluoropropane).

As shown by the Examples, according to the present invention,dichloropentafluoropropane (R225), a high-purity product of which usedto be hardly available, can be produced in good yield.

We claim:
 1. A method for producing dichloropentafluoropropane, whichcomprises reaction dichlorofluoromethane with tetrafluoroethylene in thepresence of a Lewis acid catalyst for addition reaction to obtaindichloropentafluoropropane, wherein said Lewis acid is a fluoride of theformula:

    MX.sub.α F.sub.β

wherein M is one of atoms selected from Group IVa, Group Va and GroupIIIb, or a mixture of such atoms, X is one of Cl, Br and I atoms, or amixture of such atoms, α is a real number of 0<α<5, and β is a realnumber of 0<β≦3.5 in the case of Group IVa, a real number of 0<β≦4.5 inthe case of Group Va, and a real number of 0<β≦2.5 in the case of GroupIIIb, provided that α+β is an integer of from 3 to
 5. 2. The methodaccording to claim 1, wherein the fluoride is a compound obtained byfluorinating a halogen compound of the formula:

    MX.sub.α

wherein M is one of atoms selected from Group IVa, Group Va and GroupIIIb, or a mixture of such atoms, X is one of Cl, Br, and I atoms, or amixture of such atoms, and α is α=4 in the case of Group IVa, α=5 in thecase of Group Va, and α=3 in the case of Group IIIb, with a fluorinatingagent.
 3. The method according to claim 2, wherein chlorofluorocarbon orhydrochlorofluorocarbon is used as the fluorinating agent.